On Feb. 20, 1976, freshman John Zera disappeared from a high school in suburban Milwaukee. In the early days, John's family hoped for his safe return. Later, they prayed whoever was responsible for his disappearance would be brought to justice. Finally, they clung to hope that advances in technology or someone with a guilty conscience would someday offer an explanation of what happened to their Johnny. And why.

In this episode, Milwaukee Journal Sentinel reporter Gina Barton looks at how the case began and what drew her to it.